MONDAY, Dec. 28 (HealthDay News) -- The smartphone applications that help modern-world dwellers find restaurants in Calcutta, calculate the size of a room or even read a bar code may also fuel eating disorders.

In the wrong hands, apps and other instant technology may trigger obsessional behavior by allowing teens and young adults to constantly count calories and monitor their weight and food intake, experts say.

"This has been a concern of ours," said Dr. Harry Brandt, director of the Center for Eating Disorders at Sheppard Pratt in Towson, Md. "So many high school and college students have iPhone or smartphones or BlackBerries and a wave of applications that, to individuals with eating disorders, can be very detrimental. It's a combination of obsessionality and perfectionism."

Also troubling is the possibility that weight loss and calorie-counting apps may push some vulnerable teens and young adults over the edge to anorexia or bulimia.

"Maybe a young woman doesn't yet have anorexia nervosa but begins to very carefully monitor all the foods she's eating and her caloric intake and her weight in a very rigorous way on an iPhone application and becomes so fixated on doing this that it becomes a goal to lose more and more to feel successful in that endeavor," Brandt said.

Other experts, even if they haven't yet seen an uptick in such app misuse, acknowledged that a troubling trend could be brewing.

"As you start to lose weight, as you become more starved, you can become obsessive about what you're doing," said Dr. Sara Forman, director of the outpatient eating disorders program at Children's Hospital Boston. "Often, once things get going and the more obsessive you get, then the more you're spurred on and the more inflexible you get."

Forman said she hadn't yet noticed the app phenomenon. "That doesn't mean it's not happening," she said. "We are usually a few steps behind [our patients] because there's so much technology going through us rapid fire."

Technology-based applications may provide a "smokescreen for people to convince themselves and others that what they're doing is healthy," said Dr. Michael Rich, director of the Center on Media and Child Health at Children's Hospital Boston.

But this new concern has to fit into a larger landscape of the overweight and obese. Two-thirds of Americans currently exceed a healthy body size, and, by some accounts, ever-evolving technology may actually be able to help these people.

"We have an obesity epidemic going on, so it's important to have some of these things," Forman said.

A study out of the University of North Carolina at Chapel Hill found that children who sent text messages detailing aspects of their exercise and food intake were more likely to stay in the program compared to kids who used conventional paper-and-pencil diaries (the study was not designed to look specifically at weight loss). The text messagers kept better track of their habits than did the diarists.

"Self-monitoring is one of the most important ingredients of the weight control recipe. The problem is that people do not stick to self-monitoring and thus lose track of what they are doing and do not experience weight loss," said Jennifer Shapiro, lead author of the study and scientific director of Santech, Inc. in La Jolla, Calif. "Unlike paper diaries, text messaging is quick, easy, fun, and their phones are usually with them. Text messaging allows for instant feedback, which is also very important when making behavioral changes."

Shapiro did the study while an assistant professor of psychiatry at the University of North Carolina at Chapel Hill School of Medicine.

And there are also efforts afoot to use Palm Pilots and text messaging to aid people with eating disorders, Brandt said.

"There are a lot of conflicting messages right now as a result of two different problems that require two different approaches," Brandt said. "You probably shouldn't be rigidly and compulsively monitoring your nutritional intake but should eat a wide variety of foods and not be obsessively calorie counting. The war on obesity says you have to be thinner, and the eating disorder prevention movement says you need to lighten up on yourself a bit."